Cam bar for axle lathes



May 21, 1957 R. H. OSTER ET AL 2,792,736

CAM BAR FOR AXLE LATHE-S Filed June 7, 1951 2 Sheets-Sheet J.

' INVENTORS ROBERT H.0STER And THEYODORE AZSAMBOKY HIS ATTORNEY -May 21,1957 R. H. OSTER ETAL 2,792,736

CAM BAR FOR AXLE LATHES Filed June 7, 1951 2 Sheets-Sheet 2 FIG. 3

INVENTORS ROBERT H. OSTER And HIS ATTORNEY United States Patent CAM BARFOR AXLE LATHES Robert H. Oster, Library, and Theodore A. Zsamboky,

Pittsburgh, Pa., assignors to United States Steel Corporation, acorporation of New Jersey Application June 7, 1951, Serial No. 230,400

6 Claims. (Cl. 82-14) This invention relates to an improved cam bar foraxle lathes.

In the manufacture of railroad car axles, an axle lathe is used tomachine the central portion of each axle (i. e., the portion between thetwo wheel seats) from a forged condition to a smooth finish. Such lathesinclude a longitudinally movable carriage, one or more cutting toolswhich move longitudinally with the carriage, but which can move in andout with respect to the work independently of the carriage, and a cambar for controlling this in-and-out movement. The present invention isconcerned with an improved cam bar for a recently developed axle lathethat has three cutting tools, each of which cuts approximately a thirdof the machined length. In making each cut the carriage of such a lathetravels only about a third of this machined length, thus increasing thespeed at which an axle can be machined by about threefold over a lathehaving only a single cutting tool.

Standard axles have a cylindrical section at the longitudinal center,and tapered sections at each end of this cylindrical section extendingtoward the wheel seats. The

junctures between the tapered sections and the wheel seats are rounded.The variables in different standard designs of axles are (a) the lengthof the central cylindrical section, (b) the angle of taper of thetapered sections, (0) the radius of the rounded juncture between thetapered sections and the wheel seats, and (d) the total length whichmust be machined between the wheel seats. Prior to the presentinvention, the only way of which we are aware of machining differentdesigns of axles necessitated a different cam bar for each design.

An object of the present invention is to provide an improved cam barwhich is adjustable so that it can be used for machining axles of anystandard design.

A more specific object of the invention is to provide an improved cambar which includes a holder and different individual cams mountedtherein which either are adjustable or are removable and replaceable tovary the configuration, so that the one cam bar can be used formachining all the standard designs of axles.

In accomplishing these and other objects of the invention, we haveprovided improved details of structure, a single form of which is shownin the accompanying drawings, in which:

Figure 1 is a somewhat schematic top plan view of an axle lathe of thetype with which the cam bar of the present invention can be used;

Figure 2 is a horizontal sectional view of an improved cam bar whichembodies features of the present invention;

Figure 3 is a vertical cross sectional view taken substantially on lineIIIIII of Figure 2;

Figure 4 is a top plan view of an alternative fillet cam which can beused in place of the fillet cams shown in Figure 2; and

Figures 5 and 6 are top plan. views of alternative approach cams whichcan be. used, in place of the approach cams shown in Figure 2.

2,792,736 Patented May Figure 1 shows an axle lathe which includes acarriage A, three cutting tools 131, B2 and Ba, and a cam bar C. Erepresents an axle which is mounted in the lathe for machining. Thelathe machines the two tapered sections X,- the central cylindricalsection Y, and the rounded junctures Z of this axle. The carriageillustrated moves from right to left in making a cut and the axlerotates, although it is apparent that with an appropriate drive and camarrangement the carriage could move the other way. The cam bar furnishestwo fillet cams 10 and 12, two approach earns 13 and 14, two taper cams15 and 16 and a center cam 17. The three cutting tools B1, B2 and B3have rollers F1, F2 and F3 respectively which ride along these cams forguiding the tools in and out with respect to the axle as the carriagetravels longitudinally.

Roller F1 is offset longitudinally to the right of its cutting tool;roller F2 occupies the same longitudinal position as its cutting tool;and roller F3 is offset longitudinally to the left of its cutting tool.At the start of a cut the left cam face of the fillet cam 10 guides toolB1 into the work, and the left cam faces of the approach cams 13 and 14guide tools B2 and B3 respectively into the work. The fillet cam mustprovide for forming the rounded juncture Z at the right, but the twoapproach cams merely guide their tools into the work. Next the threetools make a cut with the taper cam 15 guiding the tool E1, the tapercam 15, center cam 17 and taper cam 16 successively guiding the tool B2,and the taper cam 16 guiding the toolBs. At the conclusion of this cut,the right cam faces of the approach earns 13 and 14 guide the tools B1and B2 away from the work and the right cam face of the fillet cam 12guides the tool B3 away. This fillet cam 12 must provide for forming therounded juncture Z at the left. The longitudinal offset in the rollersF1 and F3 from their cutting tools B1 and B3 enables these tools to cutthe portions of the axles directly opposite the approach cams 13 and 14and this offset also furnishes the necessary overlap with the portion ofthe axle which tool B2 cuts. The details of the lathe apart from theimproved cam bar are not shown, since per so they are not part of thepresent invention, but can be of any standard or desired construction.

With reference to Figures 2 and 3, the cam bar of the present inventioncomprises a holder 18 which is of U-shape in cross section. The bight ofthe U forms the back face of the cam bar (i. e., the face directedtoward the work); the arms of the U form the top and bottom of the cambar; and the open end of the U forms the front of the cam bar from whichthe various cams 10 to 17 project. These cams are formed as separateparts mounted within the holder 18, and each cam is of approximatelyhalf the thickness of the space within the holder. A plurality of bolts19 affix the center cam 17 to the back of the holder. The center cam hasan outside pair of pivot openings 20 and an inside pair of pivotopenings 21. The two taper cams 15 and 16 extend from the center cam 17toward the ends of the holder. They are pivoted to the center cam 17 onbolts or pins 22 that pass through either the openings 20, asillustrated in Fig ure 2, or else the openings 21, depending on thelength of the cylindrical center section Y which is desired in themachined axles.

A plurality of abutment screws 23 are threadedly engaged with the backof the holder 18. Their inner ends abut the backs of the taper earns 15and 16. Proper adjustment of these screws adjusts the angle of the tapercams about the pins 22 and consequently adjusts the angle of taperproduced in the tapered sections X of the axle. Preferably the tapercams contain a plurality of slots 24 andthe sides of the holder 18 havescrews, 25 which pass through said slots for frictionally clamping thetaper cams in adjusted position.

The two fillet earns 10 and 12 are removably bolted to the outer endportions'of .the taper earns 15 and 16 on bolts 26. The back edges ofthe taper cams carry flanges 27 against which the fillet cams abut. Thefillet cams illustrated have two sets of openings for receiving bolts 26to furnish two different positions of adjustment. Other adjustments canbe obtained by using fillet cams of different configuration, such asthose illustrated in Figure 4. The selection and adjustment of thefillet cams controls the radius of the rounded junctures Z of themachined axle.

The two approach earns 13 and 14 are bolted to the taper camsintermediate the length of the latter on bolts 28 and they abut flanges27 on the taper cams. These approach cams are removable and replaceablewith cams of other configuration, such as those illustrated in Figuresand 6, Selection of the approach cams and positioning of the fillet camscontrols the machined length between wheel seats in the axle. The longerthe approach earns, the shorter the machined length of the axle, sincethe approach cams withhold the cutting tools from the work. Thus thecams illustrated in Figure 2 are used for an intermediate machinedlength, while those illustrated in Figures v5 and 6 are used for shorterand longer machined lengths respectively. It is seen that moving thefillet cams farther out from the position illustrated in Figure 2 alsoincreases. the machined length of the axle.

From the foregoing description it is seen that the present inventionaffords a cam bar which permits adjustability in the four variablesencountered in standard designs of railroad axles. The proper selectionand adjustment of cams enables a single cam bar to be used for machiningany standard axle, thus eliminating the need for a different cam bar forevery axle design. A further advantage in the adjustable cam bar is thatit enables ready compensation for springing of the work or the latheparts. All that is necessary to compensate for suchv springing is toadjust slightly the angle of taper of the taper cams 15 and 16.

While we have shown and described only a single embodiment of the,invention, itis apparent that modifica- .tionsmay arise. Therefore, wedo not wish to be limited to the disclosure set forth, but only by thescope of the appended claims.

We claim:

1. A cam bar for multiple tool axle lathes comprising .an elongatedholder, a center cam fixed to. themid-portion of said holder, a pair oftaper cams pivoted to said center cam and extending therefrom toward theends of said holder, adjustable. means carried by said holder foradjusting the angles of said taper cams, a pair of fillet cams removablycarried by said taper cams at the outer end portions of the latter, anda pair of approach cams removably carried by said taper .camsintermediate the length of the latter, the cam faces of said fillet andapproach cams overlapping those of the respective taper cams on whichthey are mounted, and the cam faces of said taper cams overlapping thatof said center cam.

2'. A cam bar for multiple tool axle lathes comprising an elongatedholder, a center cam fixed to the mid-portion of said holder, a pair oftaper cams pivoted to said center cam and extending therefrom toward theends of said holder, the pivot points being adjustable to vary theeffective length of the center cam, adjustable means'carried by saidholder and abutting said taper cams for adjusting the angles of thelatter, a pair of fillet cams removably and replaceably carried by saidtaper cams at the outer end portions of the latter, and a pair ofapproach cams removably and replaceably carried by said taper camsintermediate the length of the latter, the cam faces of said fillet andapproach cams overlapping 'those of the respective taper cams on whichthey are mounted, and the cam faces of said taper cams overlapping thatof said cen ter cam.

3. A cam bar for multiple tool axle lathes comprising an elongatedholder of U-shape in cross section, a center cam bolted to the insidemid-portion of said holder, a pair of taper cams pivoted to said centercam and extending therefrom toward the ends of said holder, the pivotpoints being adjustable to vary the effective length of said center cam,a plurality of abutment screws threadedly engaged with the back of saidholder and abutting the backs of said taper cams for adjusting the angleof taper, a pair of fillet cams removably and replaceably carried bysaid taper cams at the outer end portions of the latter, and a pair ofapproach cams removably and replaceably carried by said taper camsintermediate the length of the latter, said center cam, said taper cams,said fillet cams and said approach cams all projecting from the openfront of said holder, the cam faces of said fillet and approach camsoverlapping those of the respective taper cams on which they aremounted, and the cam faces of said taper cams overlapping that of saidcenter cam.

4. A cam bar for multiple tool axle lathes comprising an elongatedholder of U-shape in cross section, a center cam bolted to-the insidemid-portion of said holder, a pair of taper cams pivoted to said centercam and extending therefrom toward the ends of said holder, the

pivot points being adjustable to vary the effective length of saidcenter cam, a plurality of abutment screws threadedly engaged with theback of said holder and abutting the backs of said taper cams foradjusting the angle of taper, a flange along the back of each of saidtaper cams, a pair of fillet cams removably carried by said taper camsat the outer end portions of the latter and each abutting one of saidflanges, and a pair of approach cams removably and replaceably carriedby said taper cams intermediate the length of the latter and eachabutting one of said flanges, said center cam, said taper cams, saidfillet cams and said approach cams all projecting from the open front ofsaid holder, the cam faces of said fillet and approach cams overlappingthose of the respective taper cams on which they are mounted, and thecam faces of said taper cams overlapping that of said center cam.

5. A cam bar for multiple toolaxle lathes comprising an elongated holderof U-shape in cross section, a center cam. bolted to. the insidemid-portion of said holder, a pair of taper cams pivoted to said centercam and extending therefrom toward the ends of said holder, the pivotpoints being adjustable to vary the eifective length of said centercam,aplurality of abutment screws threadedly engaged with the back of saidholder and abutting the backs of said taper cams for adjusting the angleof taper, said taper cams having a plurality of slots,.screws threadedlyengaged with the sides of said holder and passing through said slots forclamping said taper cams in adjusted position, a'fl'ange along the backof each of said taper cams, a pair of fillet camsremovably andreplaceably carried by said taper cams'at the outer end-portions of thelatter and each abutting one of said flanges, and a pair of approachcams removably and replaceably carried by said taper cams intermediatethe length of the latter and each abutting one of said flanges, saidcenter cam, said taper cams, said fillet cams and'said approach cams allprojecting from the open front of said holder, the cam faces of saidfillet and. approach cams overlapping those of the receptive taper: camson which they are mounted, and the cam faces. of said taper camsoverlapping that of said center cam.

6. A cam bar as defined in claim 5 in which the cam faces of said tapercams are horizontally aligned and occupy approximately half thethickness of the inside of said'holder, and the cam faces- 0f saidcenter cam,- said fillet cams andsaid approach 'carns a rehorizontallyaligned and vertically offset from those ofsaidtapercams-and occupy the remainder of the thickness of the inside ofsaid holder.

References Cited in the file of this patent ONeel June 9, 1925 VanHamersveld Aug. 7, 1928 Allen Jan. 14, 1941 Himoff M Dec. 23, 1947Houghtaling June 14, 1949 Cross et a1. Feb. 6, 1951

